Benign Positional Vertigo Produces a Specific Pattern of Abnormalities with High Frequency Vestibulo-Ocular Reflex Testing

The vestibulo-ocular reflex was studied at high frequencies of active head rotation (2 to 6 Hz) in twenty-three patients with benign positional vertigo (BPPV). Gain and phase measurements were obtained in the vertical and horizontal planes, and the results were compared to those of a control group consisting of 19 asymptomatic age-matched subjects. In the horizontal plane, the phase lead was significantly smaller in patients with BPPV as compared to controls (p < 0.01 at all frequencies). Vertical results did not differ from normals. These findings challenge "cupulolithiasis" as an explanation of the mechanism of BPPV's symptoms.